Scraper assembly and material retarder for a cylindrical continuous freezer

ABSTRACT

A scraper assembly for a continuous soft ice cream freezer or the like, which assembly rotates within the freezing cylinder of the freezer and serves to scrape the product being frozen from the cylindrical inner wall of the cylinder and also serves to move the product generally from the rear of the cylinder to the front end of the cylinder where the product is drawn out. The assembly has a minimum of surface area which is exposed to the material. Scraper blades are mounted in complementary slots which are formed in the longitudinal supports forming part of the assembly and are easy to install and remove in a foolproof manner. A material retarder is stationarily mounted in the assembly to promote proper mixing of the product and is separate from but supported on both the rotatable scraper assembly and the freezer front door.

United States Patent Werner Feb. 15, 1972 [72] Inventor: Bernfried M. Werner, Pompano Beach,

Fla.

[73] Assignee: Louis A. M. Phelan, Pompano Beach, Fla.

[22] Filed: July 29, 1970 [21] Appl. No.: 59,099

[52] US. Cl ..62/343, 165/94 [51] Int. Cl. ..F25c 7/10 [58] Field of Search ..62/342, 343, 303; 165/94, 91; 259/155 [56] References Cited UNITED STATES PATENTS 3,298,190 1/1967 Harker ..62/342 2,589,350 3/1952 Edmunds, Jr. ....165/94 3,170,676 2/1965 Koch ..62/343 X 2,836,401 5/1958 Phelan ..62/343 2,746,730 5/1956 Swenson et al. ....62/343 X 2,638,329 5/1953 Weygand et al. ..165/94 X Primary ExaminerWilliam E. Wayner AttorneyJames E. Nilles [57] ABSTRACT A scraper assembly for a continuous soft ice cream freezer or the like, which assembly rotates within the freezing cylinder of the freezer and serves to scrape the product being frozen from the cylindrical inner wall of the cylinder and also serves to move the product generally from the rear of the cylinder to the front end of the cylinder where the product is drawn out. The assembly has a minimum of surface area which is exposed to the material. Scraper blades are mounted in complementary slots which are formed in the longitudinal supports forming part of the assembly and are easy to install and remove in a foolproof manner. A material retarder is stationarily mounted in the assembly to promote proper mixing of the product and is separate from but supported on both the rotatable scraper assembly and the freezer front door.

4 Claims, 15 Drawing Figures PATENTEDFEB1S1972 3.641 .783

SHEET 1 OF 4 FIG. 1

m Q lNVENTOR B.M.WERNER BY: 547M ATTORNEY PAIENTEUFEB 15 I912 3.641.783

SHEET 2 0F 4 INVENTOR BM. WERNER BY: W 57/4140 ATTORNEY PATENYEDFEB 15 I912 sum 3 or 4 INVENTORI B.M. WERNER 8% Z. 77%

ATTORNEY O u uOm 8m m- 60m I on 5m m y m m m 0K 5 N Os T RNNNHU E4 WE HM m 5, mm, m 07.. F GWEN. i 1 N PATENTEUFEBISIQIZ SHEET u 0F 4 N QUE NHOE mm w mg mm 2 m .a a m 3 0E .zw F\\ ll L xmw SCRAPER ASSEMBLY AND MATERIAL RETARDER FOR A CYLINDRICAL CONTINUOUS FREEZER BACKGROUND OF THE INVENTION This invention pertains generally to refrigeration equipment of the type having a cylindrical freezer for the continuous freezing of soft ice cream, custards or the like. The aerated mix is fed into one end of the cylinder and a rotatable scraper assembly in the cylinder acts to move the material generally around the cylinder and to the front, discharge end thereof while the material is being cooled. A scraper assembly of the general type to which the invention pertains is shown in the U.S. Pat. No. 3,061,281 issued Oct. 30, 1962, entitled Dispensing Freezer, which patent discloses a dasher assembly that is mounted for rotation on its periphery at the front end, and which also shows a retarder that is fixed to and removes with the front door of the freezer. While the device shown in that patent did perform satisfactorily, the scraper blades were mounted on rings forming part of the assembly and by mounting means which are expensive to manufacture, maintain and clean. Furthermore, when the freezer was to be disassembled for cleaning and repair, it was difficult to remove the cover and the retarder as a unit due to the frozen material left in the cylinder.

An example of a prior art device having an assembly of the above type and which also utilized longitudinal support rods is shown in the U.S. Pat. No. 2,924,952, issued Feb. 16, 1970, but that device did not utilize scraper blades nor a retarder. In the US. Pat. No. 3,050,960, issued Aug. 28, 1962, the scraper blades are mounted on and supported by the helical screw itself. The blades are subjected to considerable pressure due to the resistance of the material frozen to the inside of the cylinder wall and it is not satisfactory to support them on a helical screw due to the deformation of the screw under adverse conditions.

SUMMARY OF THE PRESENT INVENTION The present invention provides an elongated scraper assembly for use in a freezing cylinder and which assembly has front and rear supports by means of which it is centrally mounted for rotation in the cylinder. The assembly also includes helical screw means extending between and fixed to said supports, and a pair of longitudinal support rods and fixed to said supports. The rods act as support means for removable scraper blades which can be easily assembled and disassembled on the scraper assembly in such a manner that it is impossible to assemble them with their scraping edge facing in the wrong direction.

Another aspect of the invention relates to a scraper assembly for use in a freezing cylinder and also provides a material retarder which is stationarily mounted in, but detachable from the central portion of the scraper assembly. The retarder is mounted at its front end in detachable relationship with the removable front cover of the freezer. By this means, the cover can be removed from the freezer separately from the retarder, and then the retarder can be removed separately from the cylinder and scraper assembly.

The invention also provides a scraper assembly having improved scraper blades and mounting means therefor, which blades are economical to manufacture, easily assembled and disassembled and foolproof in assembling whereby the scraping edge of the blade is always presented at the proper attitude to the interior cylindrical surface of the freezer.

These and other objects and advantages of the present invention will appear hereinafter as this disclosure progresses, reference being had to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal, cross-sectional view through a continuous freezer embodying the present invention;

FIG. 2 is a side elevational view of the scraper assembly shown in FIG. 1, but on an enlarged scale;

FIG. 3 is a transverse, sectional view taken along line 33 in FIG. 2, but on an enlarged scale;

FIG. 4 is a front end elevational view of the scraper assembly, the view taken generally along the line 44 in FIG. 2, but an enlarged scale;

FIG. 5 is a sectional view taken along line 55 in FIG. 3, but on a reduced scale;

FIG. 6 is a sectional view taken along line 6-6 in FIG. 3;

FIG. 7 is a view of a blade and taken generally from line 7 7 in FIG. 3, but on an enlarged scale; and

FIG. 8 is a cross-sectional view taken along line 8-8 in FIG. 2, but on an enlarged scale.

FIG. 9 is a view similar to FIG. 7, but showing a modified form of blade;

FIG. 9 is an end view of FIG. 7.

FIG. 10 is a fragmentary view of a rod for mounting the blade of FIG. 9;

FIG. 1 l is an elevational view of the portion of the rod shown in FIG. 10, the view being taken along line l1-ll in FIG. 10;

FIG. 12 is a sectional view taken along line l2'l2 in FIG. 11;

FIG. 13 is a sectional view taken along line 13-13 in FIG. 11;

FIG. 14 is an end view of the FIG. 9 blade as mounted in the rod of FIG. 10; and

FIG. 15 is a perspective view of the scraper assembly shown in FIGS. 1 and 2 but with the retarder and blades removed.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring more particularly to FIG. 1 of the drawings, the invention has been shown in the environment of a continuous freezer for making soft ice cream, custard, or the like. The general arrangement includes a freezing cylinder C above which is mounted a mix tank T in which the fresh mix M is stored. The fresh mix is mixed with air introduced into the pump P via conduit 1, and the aerated product is then delivered by the pump through the opening 3 at the rear end of the upper portion of the freezing cylinder. The freezing cylinder has an annular freezing chamber 4 for the major portion of its length so that as the product is moved from the rear end of the cylinder to the front end, it is frozen.

A drive shaft 5 extends through the rear wall 6 of the freezing cylinder and is driven by an electric motor (not shown) or the like. The inner end 50 of the shaft is noncircular, such as being square, as shown.

At the front end of the freezing cylinder is located the removable door D having pivotally attached thereto the serving lever 8. The lever is swung in a vertical direction to raise and lower the plunger 9 so that when the plunger is raised the finished product can flow through the aperture 10 in the door and then downwardly through the discharge port 11. It will be noted that the door has a central hollow hub 14 extending centrally into the forward portion of the cylinder for a short distance. The arrangement is such that when the large screws 15 are loosened, the entire door may be removed. The inner, central portion of the door has a recess 16 therein for receiving the front end of a retarder, to be described, and which recess prevents rotation of the retarder.

If more complete description of the door and its serving valve 8 is deemed to be either necessary or desirable, reference may be had to the copending application, Ser. No. 59,100, filed 7/29/70 and entitled Freezer Door and Draw Off Valve for a Continuous Freezer.

The scraper assembly provided by the present invention includes a rear support 20 having a square hole 10a that complements and receives the shaft end 50. Thus, the assembly is mounted on the interior end of the drive shaft 5 for being rotatably driven by the shaft. A front support is provided in the form of a tubular collar 22 which is insertable over the hub 14 so that the front end of the assembly is rotationally and centrally supported on the hub. The scraper assembly also includes helical screw means 25 which is welded at its rear end by its support 20 and which at its front end is formed into a deeply pitch ring 26. The ring portion 26 of the helical screw means surrounds and is welded to the from support 22.

The helical screw means acts generally to move the product from the rear end of the cylinder to the front end where it can be discharged from the serving valve. As this assembly rotates the helical screw also generally moves the product around the interior of the cylinder so that the product is aggitated to a certain extent. Thus, the mass of the product moves generally around the cylinder in a circumferential direction and also moves axially towards the front end of the cylinder.

In order to prevent the material from simply revolving as a mass within the cylinder and not being folded over into itself as it is being moved, a stationary retarder 30 is mounted within the central portion of the assembly. This retarder takes the form of an elongated, generally U-shaped member having legs 31 and 32 that are mounted eccentrically with respect to the longitudinal axis of said cylinder, and a curved bight portion 300. The legs are rigidly secured together at their rear end by its crossmember 33 which in turn has a shaft 34 welded thereto. The shaft 34 is mounted in the sleeve 35 that is fixed to a cross plate 36 that in turn is welded to andbetween the longitudinal rods 40 and 41 of the assembly. The front end, that is bight portion 30a, of the retarder is mounted in and supported by generally hollow hub 14 and in the recess 42 (F IG. 1) in the central, inner portion of the hub. This detachable engagement of the retarder and hub prevents the retarder from revolving as the material is revolved by the scraper assembly. In this manner, the retarder acts to break up or cause the material to be kneaded as the scraper assembly rotates, thus providing good texture and mixing of the product before it is drawn off.

With the retarder of the present invention, the door D can be removed without the necessity of removing the retarder 30 along with it. For example, if frozen mix remains in the machine when it is to be disassembled, it has been a difficult task to remove both the cover and the retarder as a unit.

With the present invention, once the door has been removed, it is a relatively easy matter to withdraw the retarder separately from its bearing in the assembly and then pull it outwardly from the cylinder.

Referring again to the longitudinal support rods 40 and 41 of the assembly, these rods are fixed at their ends to the rear support 20 and the front support 22, for example as by welding. It will be noted that the rods 40 and 41 are also rigidly secured, as by welding, to the helical screw means intermediate the length of the latter, thus rigidifying and strengthening the helical screw means. Scraper blades B are removably mounted directly on the rigid and strong, longitudinal rods 40 and 41, and as these scraper blades B are of similar design to one another, only a description of one will be given.

The blades are of one piece construction having a rear bearing portion 50 including a rounded end 500. The bearing portion 50 also includes a relatively wide portion 50a and a relatively narrow portion 50b. In other words, the portion 50 is formed of two parts, one being larger than the other, and these parts are insertable in corresponding and complementary shaped slot means formed by slots 51 and 52 in the rods 40 and 41. Such interengaging means between the blades and rods prevents the assembly of the blade in the rod in the wrong manner. Thus, the sharp bevelled point 53 of the blade is always presented to the interior wall 54 of the cylinder (FIG. 3) at the right attitude for the proper scraping of the material from the wall.

As shown in FIG. 8, the portion 50 of the blade is slightly narrower than the width of the slots 51, and 52 so that a certain amount of play is provided therebetween. The blade is held in the slots by the cylinder wall, the blades having been inserted in the slots prior to the insertion of the assembly in the cylinder.

It will be noted by referring to FIG. 2, that the blades are in longitudinal overlapping position so as to cover the length of the cylinder wall.

MODIFIED FORM OF BLADES AND MOUNTING THEREOF The blades shown in FIGS. 9 to 14 inclusive also have complementary portions to correspondingly form slots in their supporting rods and therefore these blades cannot be assembled on the rods in the incorrect manner.

These blades B shown in FIGS. 9 to 14 include a relatively thick rear portion 60 which is of thinner dimension than the slot 61 formed in the rod 41'. The blade B has a rearmost portion 62 which is offset to one side of the midpoint length of the blade and this rearmost portion 62 extends through a counterslot 63 that is located in and communicates with slot 61. Thus, a portion of the blade protrudes all the way through the rod 41' and has an enlarged portion 64 protruding from the opposite side of the rod from which the sharpened edge 65 is located. The width of the enlarged portion 64 is the same as the width of the slots 60 and 63 so that the enlarged portion 64 can pass through these slots when the blade is assembled. After the blade has been assembled in the rod, it will naturally tilt to one side or the other and thereby the enlarged portion 64 holds the blade in assembled relationship on the rod, for example when the enlarged portion is withdrawn from the freezing cylinder. By offsetting the protruding portion 62 from the center of the length of the blade, it is impossible to assemble the blade in the wrong position in the rod.

RESUME The scraper assembly provided by the present invention is a particularly rigid and strong unit having a minimum amount of area exposed to the material within the cylinder. This is desira ble so as to reduce the amount of effort required to rotate the assembly, and eliminate difficult cleaning problems because the material itself is extremely coadhesive. In addition, such an assembly is economical to manufacture and not subject to malfunction, as it is sufficiently rigid to resist the considerable twisting and bending manipulations to which such an assembly is subjected. The retarder can be separately and easily inserted and detached from both the assembly and the removable door.

The blades themselves are economical to manufacture, easily inserted, and removed and cannot be assembled in the wrong position.

I claim:

1. In a freezing cylinder, an elongated scraper assembly comprising, a rear support and a front support for rotatably and centrally mounting said assembly about its longitudinal axis in said cylinder, helical screw means extending between and fixed to said supports, a pair of longitudinal support rods extending between and fixed to said supports, said rods also fixed to said screw means intermediate the length thereof for rigidifying said screw means, and scraper blades removably mounted on said rods along the length thereof, said rods have longitudinally extended slot means therein, and said blades being freely insertable in said slot means for being removably mounted on said rods.

2. The assembly of claim 1 wherein said slot means comprises sections of different size, and said blades have portions of complementary size to said sections whereby said blades can only be inserted in said slot means in one position.

3. The combination set forth in claim 1 wherein said freezing cylinder has a removable front cover including a hub extending centrally into said cylinder, and a stationary retarder located centrally within said assembly, said retarder having a rear end journaled in said assembly, said retarder having a front end detachably connected within said hub whereby when said cover is removed, said retarder remains in said assembly within the cylinder for separate removal of the retarder from said assembly and cylinder.

4. The combination set forth in claim 3 further characterized in that said retarder is an elongated, U-shaped member having a curved bight portion, said portion is insertable in said hub for support thereby. 

1. In a freezing cylinder, an elongated scraper assembly comprising, a rear support and a front support For rotatably and centrally mounting said assembly about its longitudinal axis in said cylinder, helical screw means extending between and fixed to said supports, a pair of longitudinal support rods extending between and fixed to said supports, said rods also fixed to said screw means intermediate the length thereof for rigidifying said screw means, and scraper blades removably mounted on said rods along the length thereof, said rods have longitudinally extended slot means therein, and said blades being freely insertable in said slot means for being removably mounted on said rods.
 2. The assembly of claim 1 wherein said slot means comprises sections of different size, and said blades have portions of complementary size to said sections whereby said blades can only be inserted in said slot means in one position.
 3. The combination set forth in claim 1 wherein said freezing cylinder has a removable front cover including a hub extending centrally into said cylinder, and a stationary retarder located centrally within said assembly, said retarder having a rear end journaled in said assembly, said retarder having a front end detachably connected within said hub whereby when said cover is removed, said retarder remains in said assembly within the cylinder for separate removal of the retarder from said assembly and cylinder.
 4. The combination set forth in claim 3 further characterized in that said retarder is an elongated, U-shaped member having a curved bight portion, said portion is insertable in said hub for support thereby. 